Atlanta — It's little wonder that the Republican-dominated Georgia Legislature waited until the closing days of its sessionto take up HB 87, an immigration reform law inspired by Arizona's controversial move last year to crack down on illegal immigrants.

Two tidal forces within the Republican Party are pulling at the Georgia bill, which has to be resolved by a Thursday midnight deadline. On one side are law-and-order Republicans who form the party's urban and suburban base, reacting to fears that illegal immigrants are in essence part of a large criminal cartel that siphons off billions in taxpayer-funded entitlements every year.

On the other are state farmers and agri-businesses, many of them financial supporters of the state GOP, who say the proposed requirements for them to check the immigration status of their quickly-hired field workers are too onerous and could, in the worst case, leave fields of Vidalia onions and groves of peach trees unpicked. Others worry that HB 87 could spark national boycotts – as the Arizona law did – and hurt the state's New South image as a diverse, newcomer-friendly place to live, work and do business.

That a Southern agricultural state may line up shoulder to shoulder with a Western border state with a vastly different economic and cultural history shows how deeply the debate over what to do with America's 13 million undocumented residents has cut into capitol dome politics.

The measure also promises to test how a bevy of new state immigration proposals will play in non-border states where Republicans are eager to challenge Washington on immigration enforcement and other perceived excesses and failures of federal power.

"What you're seeing in Georgia is what you're seeing across the country, where the demographics of immigration have changed substantially in the past 20 years," says Kevin Johnson, an immigration law expert at the University of California, at Davis. At the same time, state immigration laws "are a very difficult political issue to peg," he says, because there's dissension in both political parties over how to deal with the problem.

Bills introduced in 30 states

As of March, lawmakers in 30 US states had introduced 52 immigration-related bills, many including language similar to the Arizona law. Fourteen of those measures have failed and 36 are still pending, reports the National Conference of State Legislatures.

So far, Utah is the only state to follow Arizona's lead. Utah now requires police officers to verify the residency status of anyone detained for a serious crime. (Conceding immigrants' role in the agriculture economy, however, the Utah law provides a form of amnesty by making illegals part of a new state guest worker program – though legal experts say such a program needs congressional approval.)

If passed, Georgia's law is likely to look more like the one passed in Arizona, allowing law enforcement to question a person's immigration status based on "reasonable suspicion" that the person is in the US illegally.

"It makes perfect sense that Arizona was at the lead of these measures, because it's ground zero for illegal immigration, but it also makes sense that Georgia would be active, because Georgia is now one of the top illegal immigration destinations," says Mark Krikorian, director of the Center for Immigration Studies, a nonpartisan Washington think tank that focuses on the consequences of legal and illegal immigration for US society.

Bill moving toward passage

But the question over how tough Georgia should get has been a vexing one for Republicans. The Senate watered down a tougher House bill on Monday, taking out a requirement that all employers use the federal E-Verify system to check the residency status of workers. (The Supreme Court is expected to hand down a ruling soon on whether states can force employers to use E-Verify for all new hires.) The House threw those changes out the next day, sending the original bill back to the Senate.

On Thursday afternoon, the bill continued to move toward passage, according to Senate sources, as legislators debated giving farmers and businesses a grace period under which to comply with the law before receiving penalties.

If passed, the Georgia law is likely to meet immediate legal scrutiny. On Monday, the 9th Circuit Court of Appeals joined other federal appeals courts – including the 3rd and 10th – in shooting down local preemption of federal immigration laws. The 9th Circuit, in San Francisco, found that the Arizona law – SB 1070 – went too far by giving police new powers to demand identification from suspects and sided with a lower court ruling that the law treads on federal jurisdictions by establishing state criminal penalties for immigration-related crimes. Like the Arizona law, the Georgia bill also creates new criminal categories related to illegal immigration, including making the harboring of an illegal immigrant a crime.

Fears of Mexican cartels

For many Georgians, the bill addresses growing fears about Mexican cartels using local immigrant communities as cover for drug-trafficking, and in the process bringing the bloody Mexican drug wars closer to home. Announcing over 600 arrests as part of Operation Southern Tempest, which focused on 168 US cities, including Atlanta, Immigration and Customs Enforcement Director John Morton said in early March, "These people are up to the worst sort of violent crimes in the communities they live in. These guys aren't in book clubs, they're in violent street gangs."

"The cartel issue is what drives fears – and they're not irrational or groundless," says Mr. Krikorian.

Critics of state immigration crackdowns, however, point out that the Obama administration has taken action to resolve complaints about federal immigration enforcement, especially when dealing with violent criminals. The Department of Homeland Security deported more illegal immigrants last year – more than 400,000 – than any other US administration in history.

Another way to explain how two vastly different states are reaching the same conclusion on how to tackle the social and economic costs of illegal immigration is that such efforts are, in essence, a burgeoning form of protest by rising Republican majorities in the states, as conservatives tease out themes and policies likely to pay dividends in the 2012 election. It's not a settled debate on the right. On Thursday, Indiana Gov. Mitch Daniels (R) – a potential presidential contender – said he opposes the Arizona-style law enforcement provisions that are part of an Indiana immigration proposal.

"These laws right now are more symbolic than real," says Mr. Johnson, the immigration law expert at UC-Davis.